Avoid data race syncing secrets

internal/ingress/controller/store/backend_ssl.go

@@ -37,6 +37,9 @@ import (
 // disk to allow copy of the content of the secret to disk to be used
 // by external processes.
 func (s k8sStore) syncSecret(key string) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
 	glog.V(3).Infof("starting syncing of secret %v", key)
 
 	// TODO: getPemCertificate should not write to disk to avoid unnecessary overhead

internal/ingress/controller/store/store.go

@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"reflect"
+	"sync"
 	"time"
 
 	"github.com/golang/glog"
@@ -182,6 +183,8 @@ type k8sStore struct {
 	filesystem file.Filesystem
 
 	updateCh chan Event
+
+	mu *sync.Mutex
 }
 
 // New creates a new object store to be used in the ingress controller
@@ -200,6 +203,7 @@ func New(checkOCSP bool,
 		filesystem:         fs,
 		updateCh:           updateCh,
 		backendConfig:      ngx_config.NewDefault(),
+		mu:                 &sync.Mutex{},
 	}
 
 	eventBroadcaster := record.NewBroadcaster()